rc.firewall revision 81618
1284990Scy# Copyright (c) 1996 Poul-Henning Kamp 2284990Scy# All rights reserved. 3284990Scy# 4284990Scy# Redistribution and use in source and binary forms, with or without 5284990Scy# modification, are permitted provided that the following conditions 6284990Scy# are met: 7284990Scy# 1. Redistributions of source code must retain the above copyright 8284990Scy# notice, this list of conditions and the following disclaimer. 9284990Scy# 2. Redistributions in binary form must reproduce the above copyright 10284990Scy# notice, this list of conditions and the following disclaimer in the 11284990Scy# documentation and/or other materials provided with the distribution. 12284990Scy# 13284990Scy# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 14284990Scy# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15284990Scy# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16284990Scy# ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 17284990Scy# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18284990Scy# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19284990Scy# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20284990Scy# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21284990Scy# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22284990Scy# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23284990Scy# SUCH DAMAGE. 24284990Scy# 25290000Sglebius# $FreeBSD: head/etc/rc.firewall 81618 2001-08-14 05:50:19Z dd $ 26290000Sglebius# 27290000Sglebius 28290000Sglebius# 29294904Sdelphij# Setup system for firewall service. 30284990Scy# 31284990Scy 32284990Scy# Suck in the configuration variables. 33284990Scyif [ -z "${source_rc_confs_defined}" ]; then 34290000Sglebius if [ -r /etc/defaults/rc.conf ]; then 35290000Sglebius . /etc/defaults/rc.conf 36290000Sglebius source_rc_confs 37290000Sglebius elif [ -r /etc/rc.conf ]; then 38290000Sglebius . /etc/rc.conf 39290000Sglebius fi 40294904Sdelphijfi 41284990Scy 42284990Scy############ 43284990Scy# Define the firewall type in /etc/rc.conf. Valid values are: 44290000Sglebius# open - will allow anyone in 45290000Sglebius# client - will try to protect just this machine 46284990Scy# simple - will try to protect a whole network 47284990Scy# closed - totally disables IP services except via lo0 interface 48284990Scy# UNKNOWN - disables the loading of firewall rules. 49284990Scy# filename - will load the rules in the given filename (full path required) 50284990Scy# 51290000Sglebius# For ``client'' and ``simple'' the entries below should be customized 52284990Scy# appropriately. 53284990Scy 54284990Scy############ 55284990Scy# 56284990Scy# If you don't know enough about packet filtering, we suggest that you 57284990Scy# take time to read this book: 58284990Scy# 59294904Sdelphij# Building Internet Firewalls, 2nd Edition 60294904Sdelphij# Brent Chapman and Elizabeth Zwicky 61294904Sdelphij# 62294904Sdelphij# O'Reilly & Associates, Inc 63294904Sdelphij# ISBN 1-56592-871-7 64294904Sdelphij# http://www.ora.com/ 65294904Sdelphij# http://www.oreilly.com/catalog/fire2/ 66284990Scy# 67284990Scy# For a more advanced treatment of Internet Security read: 68284990Scy# 69# Firewalls & Internet Security 70# Repelling the wily hacker 71# William R. Cheswick, Steven M. Bellowin 72# 73# Addison-Wesley 74# ISBN 0-201-63357-4 75# http://www.awl.com/ 76# http://www.awlonline.com/product/0%2C2627%2C0201633574%2C00.html 77# 78 79if [ -n "${1}" ]; then 80 firewall_type="${1}" 81fi 82 83############ 84# Set quiet mode if requested 85# 86case ${firewall_quiet} in 87[Yy][Ee][Ss]) 88 fwcmd="/sbin/ipfw -q" 89 ;; 90*) 91 fwcmd="/sbin/ipfw" 92 ;; 93esac 94 95############ 96# Flush out the list before we begin. 97# 98${fwcmd} -f flush 99 100############ 101# Network Address Translation. All packets are passed to natd(8) 102# before they encounter your remaining rules. The firewall rules 103# will then be run again on each packet after translation by natd 104# starting at the rule number following the divert rule. 105# 106# For ``simple'' firewall type the divert rule should be put to a 107# different place to not interfere with address-checking rules. 108# 109case ${firewall_type} in 110[Oo][Pp][Ee][Nn]|[Cc][Ll][Ii][Ee][Nn][Tt]) 111 case ${natd_enable} in 112 [Yy][Ee][Ss]) 113 if [ -n "${natd_interface}" ]; then 114 ${fwcmd} add 50 divert natd all from any to any via ${natd_interface} 115 fi 116 ;; 117 esac 118esac 119 120############ 121# If you just configured ipfw in the kernel as a tool to solve network 122# problems or you just want to disallow some particular kinds of traffic 123# then you will want to change the default policy to open. You can also 124# do this as your only action by setting the firewall_type to ``open''. 125# 126# ${fwcmd} add 65000 pass all from any to any 127 128############ 129# Only in rare cases do you want to change these rules 130# 131${fwcmd} add 100 pass all from any to any via lo0 132${fwcmd} add 200 deny all from any to 127.0.0.0/8 133${fwcmd} add 300 deny ip from 127.0.0.0/8 to any 134# If you're using 'options BRIDGE', uncomment the following line to pass ARP 135#${fwcmd} add 400 pass udp from 0.0.0.0 2054 to 0.0.0.0 136 137 138# Prototype setups. 139# 140case ${firewall_type} in 141[Oo][Pp][Ee][Nn]) 142 ${fwcmd} add 65000 pass all from any to any 143 ;; 144 145[Cc][Ll][Ii][Ee][Nn][Tt]) 146 ############ 147 # This is a prototype setup that will protect your system somewhat 148 # against people from outside your own network. 149 ############ 150 151 # set these to your network and netmask and ip 152 net="192.0.2.0" 153 mask="255.255.255.0" 154 ip="192.0.2.1" 155 156 # Allow any traffic to or from my own net. 157 ${fwcmd} add pass all from ${ip} to ${net}:${mask} 158 ${fwcmd} add pass all from ${net}:${mask} to ${ip} 159 160 # Allow TCP through if setup succeeded 161 ${fwcmd} add pass tcp from any to any established 162 163 # Allow IP fragments to pass through 164 ${fwcmd} add pass all from any to any frag 165 166 # Allow setup of incoming email 167 ${fwcmd} add pass tcp from any to ${ip} 25 setup 168 169 # Allow setup of outgoing TCP connections only 170 ${fwcmd} add pass tcp from ${ip} to any setup 171 172 # Disallow setup of all other TCP connections 173 ${fwcmd} add deny tcp from any to any setup 174 175 # Allow DNS queries out in the world 176 ${fwcmd} add pass udp from ${ip} to any 53 keep-state 177 178 # Allow NTP queries out in the world 179 ${fwcmd} add pass udp from ${ip} to any 123 keep-state 180 181 # Everything else is denied by default, unless the 182 # IPFIREWALL_DEFAULT_TO_ACCEPT option is set in your kernel 183 # config file. 184 ;; 185 186[Ss][Ii][Mm][Pp][Ll][Ee]) 187 ############ 188 # This is a prototype setup for a simple firewall. Configure this 189 # machine as a named server and ntp server, and point all the machines 190 # on the inside at this machine for those services. 191 ############ 192 193 # set these to your outside interface network and netmask and ip 194 oif="ed0" 195 onet="192.0.2.0" 196 omask="255.255.255.240" 197 oip="192.0.2.1" 198 199 # set these to your inside interface network and netmask and ip 200 iif="ed1" 201 inet="192.0.2.16" 202 imask="255.255.255.240" 203 iip="192.0.2.17" 204 205 # Stop spoofing 206 ${fwcmd} add deny all from ${inet}:${imask} to any in via ${oif} 207 ${fwcmd} add deny all from ${onet}:${omask} to any in via ${iif} 208 209 # Stop RFC1918 nets on the outside interface 210 ${fwcmd} add deny all from any to 10.0.0.0/8 via ${oif} 211 ${fwcmd} add deny all from any to 172.16.0.0/12 via ${oif} 212 ${fwcmd} add deny all from any to 192.168.0.0/16 via ${oif} 213 214 # Stop draft-manning-dsua-03.txt (1 May 2000) nets (includes RESERVED-1, 215 # DHCP auto-configuration, NET-TEST, MULTICAST (class D), and class E) 216 # on the outside interface 217 ${fwcmd} add deny all from any to 0.0.0.0/8 via ${oif} 218 ${fwcmd} add deny all from any to 169.254.0.0/16 via ${oif} 219 ${fwcmd} add deny all from any to 192.0.2.0/24 via ${oif} 220 ${fwcmd} add deny all from any to 224.0.0.0/4 via ${oif} 221 ${fwcmd} add deny all from any to 240.0.0.0/4 via ${oif} 222 223 # Network Address Translation. This rule is placed here deliberately 224 # so that it does not interfere with the surrounding address-checking 225 # rules. If for example one of your internal LAN machines had its IP 226 # address set to 192.0.2.1 then an incoming packet for it after being 227 # translated by natd(8) would match the `deny' rule above. Similarly 228 # an outgoing packet originated from it before being translated would 229 # match the `deny' rule below. 230 case ${natd_enable} in 231 [Yy][Ee][Ss]) 232 if [ -n "${natd_interface}" ]; then 233 ${fwcmd} add divert natd all from any to any via ${natd_interface} 234 fi 235 ;; 236 esac 237 238 # Stop RFC1918 nets on the outside interface 239 ${fwcmd} add deny all from 10.0.0.0/8 to any via ${oif} 240 ${fwcmd} add deny all from 172.16.0.0/12 to any via ${oif} 241 ${fwcmd} add deny all from 192.168.0.0/16 to any via ${oif} 242 243 # Stop draft-manning-dsua-03.txt (1 May 2000) nets (includes RESERVED-1, 244 # DHCP auto-configuration, NET-TEST, MULTICAST (class D), and class E) 245 # on the outside interface 246 ${fwcmd} add deny all from 0.0.0.0/8 to any via ${oif} 247 ${fwcmd} add deny all from 169.254.0.0/16 to any via ${oif} 248 ${fwcmd} add deny all from 192.0.2.0/24 to any via ${oif} 249 ${fwcmd} add deny all from 224.0.0.0/4 to any via ${oif} 250 ${fwcmd} add deny all from 240.0.0.0/4 to any via ${oif} 251 252 # Allow TCP through if setup succeeded 253 ${fwcmd} add pass tcp from any to any established 254 255 # Allow IP fragments to pass through 256 ${fwcmd} add pass all from any to any frag 257 258 # Allow setup of incoming email 259 ${fwcmd} add pass tcp from any to ${oip} 25 setup 260 261 # Allow access to our DNS 262 ${fwcmd} add pass tcp from any to ${oip} 53 setup 263 ${fwcmd} add pass udp from any to ${oip} 53 264 ${fwcmd} add pass udp from ${oip} 53 to any 265 266 # Allow access to our WWW 267 ${fwcmd} add pass tcp from any to ${oip} 80 setup 268 269 # Reject&Log all setup of incoming connections from the outside 270 ${fwcmd} add deny log tcp from any to any in via ${oif} setup 271 272 # Allow setup of any other TCP connection 273 ${fwcmd} add pass tcp from any to any setup 274 275 # Allow DNS queries out in the world 276 ${fwcmd} add pass udp from ${oip} to any 53 keep-state 277 278 # Allow NTP queries out in the world 279 ${fwcmd} add pass udp from ${oip} to any 123 keep-state 280 281 # Everything else is denied by default, unless the 282 # IPFIREWALL_DEFAULT_TO_ACCEPT option is set in your kernel 283 # config file. 284 ;; 285 286[Uu][Nn][Kk][Nn][Oo][Ww][Nn]) 287 ;; 288*) 289 if [ -r "${firewall_type}" ]; then 290 ${fwcmd} ${firewall_flags} ${firewall_type} 291 fi 292 ;; 293esac 294